MURRAY RIVER

principal river of Australia, flowing 1,609 miles (2,589 km) across southeastern Australia from the Snowy Mountains to the Great Australian Bight of the Indian Ocean. Although it has a total catchment area of 414,253 square miles (1,072,905 square km), its average annual discharge is only 31 cubic feet (0.89 cubic m) per second, and in places it has dried up on at least three occasions. Named after Colonial Secretary Sir George Murray, the river rises on The Pilot (a mountain), near Mount Kosciusko in southeastern New South Wales. It flows west and northwest, passes through Hume Reservoir above Albury, and forms most of the boundary between New South Wales and Victoria. At Morgan, S.Aus., it bends sharply southward to flow through Lake Alexandrina to Encounter Bay on the Great Australian Bight. For most of its course through South Australia (250 miles ), the river is bordered by a narrow floodplain and flows between cliffs 100 feet (30 m) high. Its upper 200 miles (320 km) cut through mountainous terrain. The central section, however, lies on a broad and mature floodplain, with the Riverina plains of New South Wales to the north and the plains of northern Victoria to the south. Its principal tributaries are the Darling River, Murrumbidgee River, Mitta Mitta, Ovens, Goulburn, Campaspe, and Loddon rivers. The Murray Valley is of immense economic significance, lying across the great wheatsheep belt in its climatically most reliable section. During the second half of the 19th century, river shipping was of great importance, but, with growing competition from railways and demand for irrigation water (first used at Mildura, 1886), navigation practically ceased. The valley has by far the most considerable irrigation (more than 1,000,000 acres [400,000 hectares]) of the continent. Its chief products are cattle, sheep, grains, fruit, and wine. In 1915 the River Murray Commission, comprising representatives from the three state governments and the commonwealth, was established to regulate utilization of the river's waters. The largest reservoirs are the Dartmouth on the Mitta Mitta River and the Hume on the Murray. Dartmouth's dam, 180 m (591 feet) high, is the highest dam in the southern hemisphere. The multipurpose Snowy Mountains scheme (completed in 1974), increased the amount of water available for irrigation and generated large quantities of electrical power for peak load periods. Irrigation, however, led to serious salinity problems, so much so that Adelaide (which is almost completely dependent on the Murray for its water supply) on occasion has received water that, by World Health Organization (WHO) criteria, is unfit for drinking. The problem of Murray salinity has been recognized as of national significance to Australia. Principal towns in the Murray Valley are Albury, Echuca, Swan Hill, Mildura, Renmark, and Murray Bridge.